1. Field of the Invention
The present invention relates to an inkjet head driving apparatus and an inkjet driving method.
2. Description of the Related Art
Generally, in order to perform high quality printing, an inkjet printer utilizes an area gradation system, such as a dither system. This system forms a matrix of plural dots, namely a pixel, without changing the size of an ink drop and represents gradation by different numbers of dots in pixels. The system obtains gradation higher than a certain level at the expense of resolution.
Another known technology is a density gradation system, which changes the density of one dot by changing the size of an ink drop. This system does not sacrifice resolution but involves a difficult technology in seeking to control the size of ink drops.
A so-called multi-drop drive system is also known. In this system, the number of ink drops projected per dot is changed without changing the size of individual drops, thereby creating density gradation. This system involves no sacrifice of gradation and obviates the need to control the size of ink drops. Accordingly, this system can be comparatively easily realized from a technical point of view (refer to Japanese Patent No. 2931817.